8861021689 has 15 divisors (see below), whose sum is σ = 9616679387. Its totient is φ = 8164719888.

The previous prime is 8861021657. The next prime is 8861021723. The reversal of 8861021689 is 9861201688.

The square root of 8861021689 is 94133.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 7 ways, for example, as 6968075625 + 1892946064 = 83475^2 + 43508^2 .

It is not a de Polignac number, because 8861021689 - 2⁵ = 8861021657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8861021189) by changing a digit.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 15908199 + ... + 15908755.

Almost surely, 2^8861021689 is an apocalyptic number.

8861021689 is the 94133-rd square number.

8861021689 is the 47067-th centered octagonal number.

It is an amenable number.

8861021689 is a deficient number, since it is larger than the sum of its proper divisors (755657698).

8861021689 is an frugal number, since it uses more digits than its factorization.

8861021689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1166 (or 570 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 49.

The cubic root of 8861021689 is about 2069.3213244170.

Multiplying 8861021689 by its sum of digits (49), we get a square (434190062761 = 658931²).

The spelling of 8861021689 in words is "eight billion, eight hundred sixty-one million, twenty-one thousand, six hundred eighty-nine".